We know about this one. How many others? And who did Rosen email during those days whose information is now in the hands of the DOJ? More from WaPo story:

Court documents in the Kim case reveal how deeply investigators explored the private communications of a working journalist — and raise the question of how often journalists have been investigated as closely as Rosen was in 2010. The case also raises new concerns among critics of government secrecy about the possible stifling effect of these investigations on a critical element of press freedom: the exchange of information between reporters and their sources.